How do I prepare for an Old One's Army event in Terraria?

Preparing for the Old One's Army event in Terraria requires careful planning, as it is one of the most challenging events in the game. This event is tied to the Tavernkeep NPC, who sells Defender Medals used to purchase powerful sentry weapons and armor. The Old One's Army is a wave-based defense event where you must protect the Eternia Crystal from waves of enemies. HereÔÇÖs a detailed guide to help you prepare effectively.

First, you need to understand the mechanics of the event. The Old One's Army has three tiers, each unlocked at different stages of progression. Tier 1 is available after defeating the Eye of Cthulhu or Brain of Cthulhu/Eater of Worlds. Tier 2 unlocks after defeating a mechanical boss, and Tier 3 becomes available after defeating Plantera. Each tier increases in difficulty, with stronger enemies and more waves. The event takes place at the Eternia Crystal Stand, which you can place anywhere in the world. You must defend the crystal from enemies that spawn from portals on either side of the arena. If the crystal is destroyed, the event ends in failure.

To prepare for the event, start by building a suitable arena. The arena should be flat and wide, with enough space to place sentries and maneuver around. A good size is around 100 blocks wide, with the Eternia Crystal Stand placed in the center. Place platforms or blocks to create multiple layers, allowing you to move vertically and avoid enemy attacks. You can also build walls or barriers to funnel enemies into specific paths, making it easier to defend the crystal. However, avoid blocking the entire area, as some enemies can fly or teleport.

Next, gather the necessary resources and equipment. For Tier 1, youÔÇÖll need basic armor and weapons, such as Gold or Platinum armor and a decent ranged or melee weapon. For Tier 2, upgrade to stronger armor like Adamantite or Titanium, and use weapons like the Megashark or Daedalus Stormbow. For Tier 3, youÔÇÖll need endgame gear like Beetle or Spectre armor, along with powerful weapons such as the Terra Blade or Stardust Dragon Staff. Sentry weapons are crucial for this event, so purchase them from the Tavernkeep using Defender Medals. The Ballista Staff is particularly effective for its high damage output.

Class and equipment considerations are important. The Summoner class is highly effective for this event due to its ability to summon multiple minions and sentries. However, any class can succeed with the right setup. Melee players should focus on high-defense armor and weapons with area-of-effect damage. Ranged players should use weapons with high DPS and mobility. Mages should prioritize spells with crowd control and high damage. Regardless of your class, always bring healing potions, buff potions like Ironskin and Regeneration, and mobility accessories like Wings or Lightning Boots.

During the event, prioritize defending the crystal over killing enemies. Use sentries to create a defensive line, and focus on taking out high-priority targets like flying enemies or bosses. Keep an eye on the crystalÔÇÖs health and repair it if it takes damage. Repairing the crystal costs mana, so bring mana potions if youÔÇÖre not playing as a Mage. Use your mobility to avoid enemy attacks and reposition as needed.

Common mistakes to avoid include neglecting to build a proper arena, underestimating the importance of sentries, and focusing too much on killing enemies instead of defending the crystal. Another mistake is not preparing enough healing items or buffs, which can lead to quick defeats. Advanced techniques include optimizing sentry placement to maximize damage and using traps or environmental hazards to weaken enemies. For example, you can place lava pits or dart traps along enemy paths to deal extra damage.

Resource requirements and preparation vary depending on the tier. For Tier 1, youÔÇÖll need basic ores and materials to craft armor and weapons. For Tier 2, youÔÇÖll need Hardmode ores and stronger weapons. For Tier 3, youÔÇÖll need endgame materials like Chlorophyte and Luminite. Always stock up on Defender Medals by completing lower-tier events before attempting higher tiers.

In summary, preparing for the Old One's Army event involves building a well-designed arena, gathering the right equipment, and understanding the eventÔÇÖs mechanics. Focus on defending the crystal, use sentries effectively, and avoid common mistakes. With proper preparation and strategy, you can successfully complete the event and earn valuable rewards.